panic when inserting USB drive into 5.2.1R machine

Hi,
I've just bought a new USB flash drive and it causes a panic on my machine.
The motherboard is an nForce2 (dmesg can be sent to anyone who requests it).
The offending messages are:
===On Insertion===
Aug 21 14:22:37 congo kernel: umass0: vendor 0x0ef8 PANRAM, rev 1.10/1.00,
addr 3
Aug 21 14:22:42 congo kernel: umass0: Invalid CSW: tag 3 should be 1
Aug 21 14:22:42 congo kernel: umass0: Invalid CSW: tag 1 should be 2
Aug 21 14:22:42 congo kernel: umass0: Invalid CSW: tag 1 should be 3
===Panic message====
savecore: reboot after panic: ohci_add_done: addr 0x1d074f60 not found
===GDB backtrace===
#0 doadump () at /usr/src/sys/kern/kern_shutdown.c:240
#1 0xc04f6fda in boot (howto=256) at /usr/src/sys/kern/kern_shutdown.c:372
#2 0xc04f7358 in panic () at /usr/src/sys/kern/kern_shutdown.c:550
#3 0xc048ea08 in ohci_add_done (sc=0xc4823000, done=487018336)
at /usr/src/sys/dev/usb/ohci.c:1320
#4 0xc048e7d9 in ohci_intr1 (sc=0xc4823000)
at /usr/src/sys/dev/usb/ohci.c:1212
#5 0xc048e65f in ohci_intr (p=0xc4823000) at /usr/src/sys/dev/usb/ohci.c:1142
#6 0xc04e25d8 in ithread_loop (arg=0xc204c880)
at /usr/src/sys/kern/kern_intr.c:544
#7 0xc04e132f in fork_exit (callout=0xc04e2410 <ithread_loop>, arg=0x0,
frame=0x0) at /usr/src/sys/kern/kern_fork.c
The only thing i've come across when looking through the archives is
http://lists.freebsd.org/pipermail/freebsd-current/2004-January/018826.html,
which isn't too helpful, and since i've used other USB flash drives before
with no problems I would doubt a chipset error.
Any help is appreciated. Although I haven't yet upgraded to 5.3-BETA I am
considering it to see if this fixes it
Steve